Printing systems are known in which print data is transferred from a printing apparatus control unit in the form of a host computer to a printing apparatus in the form of a printer for hardcopy printout. Some of them perform different procedure to handle image data from procedure to handle other type of data.
JP-A 7-306760 discloses a printing system in which a host computer analyzes print data and predicts transfer time required for data transfer if the data is transferred in a first format and predicts transfer time required for data transfer if the data is transferred in a second format. The host computer compares the predicted transfer times with each other and selects one of the first and second formats for data transfer in response to the comparison result for shortening the overall time required for printing the data.
JP-A 6-199000 discloses a printing system including a host computer and a plurality of printers in communication with the host computer. The host computer stores a table containing information as to fonts stored in each of the printers. The host computer analyzes print data and looks into the table and predicts data quantities for data transfer to all of printers. The host computer selects one of the printers, which needs the least data quantity for data transfer thereto, and then initiates transfer of the print data to the selected printer.
A host computer can handle different types of print data, such as character data, drawing data and bit image data. The host computer and a printer share data processing to convert these data into a synthesized bit image data for hardcopy printout. Different types of print data demand different times and data processing for conversion into bit image data. Print data is different in data quantity from bit image data resulting from conversion thereof.
Throughput of a host computer determines time required for processing data. Different computers have different throughputs, respectively. Thus, they need different lengths of time in processing the same data. Throughput of a printer determines time required for processing data. Different printers have different throughputs, respectively, thus requiring different lengths of time in processing the same data. Time required for data transfer between a host computer and a printer depends on throughput of the host computer, throughput of the printer and throughput of an interface between the host computer and the printer.
Printing systems are not yet known which conduct optimum distribution of data processing between a host computer and a printer after consideration of throughputs of the system components to provide shortest time data processing for translating print data to bit image data for hardcopy printout.